Trouble Serializing a Class Object

[remnant]

I'm having a problem serializing a class object.

Page 1:

session_start();
include("class.php");
$obj = new Class;

code / content here

$_SESSION['obj'] = $obj;

Page 2:

include("class.php");
session_start();
$obj = $_SESSION['obj'];

When I get to page 2 from page 1, I receive the following error:

Fatal error: The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition class of the object you are trying to operate on was loaded before the session was started in index.php on line 19

If I do a var_dump of $obj on page 2, I get the following:

object(__PHP_Incomplete_Class)

Any help would be greatly appreciated.

Thanks in advance

[thorpe]

where are you serializing it?

session_start(); 
include("class.php"); 
$obj = new Class; 

code / content here 

$_SESSION['obj'] = serialize($obj);

then on the next page;

include("class.php"); 
session_start(); 
$obj = unserialize($_SESSION['obj']);

[remnant]

All session variables are serialized, so $_SESSION['obj'] = serialize($obj); should do it.

[thorpe]

All session variables are serialized, so $_SESSION['obj'] = serialize($obj); should do it.

so.... is it working now?

[remnant]

No, I haven't made any changes.

saying:

$_SESSION['obj'] = $obj;

is equilaent to:

$var = serialize($obj);

I think I may see where the problem is, but I'm unsure.
The class definition of Obj extends another class which in turn has private variables for subclass instances. From the PHP manual, I found a comment which may help. I'll repost it here:

A quick note about objects containing another object as a variable. Say you have something like this:

class A {
var $A_Var;
}

class B {
var $A
var $B_Var;
function B() {
$this->A = new A();
}
}

$B = new B();
$B->A->A_Var = "A_Var value";

---

When you try to serialize() an instance of B() $B->A->A_Var doesn't seem to keep it's value.

After much fighting with this the solution I found was to append to my sleep and wakeup functions and serialize $this->A in sleep and then unserialize it in wakeup.

class A {
var $A_Var;
}

class B {
var $A
var $A_serialized;
var $B_Var;
function B() {
$this->A = new A();
}

function sleep() {
$this->A_serialized = serialize($this->A);
return array('A_serialized', 'B_Var');
}
function wakeup() {
$this->A = unserialize($this->A_serialized);
}
}

[remnant]

All is working now.

Here is how it looks.

Page 1:

session_start(); 
include("class.php"); 
$obj = new Class; 

code / content

$serializedObj = serialize($obj);
$_SESSION['serializedObj'] = $serializedObj;

Page 2:

session_start();
include("class.php"); 
$obj = unserialize($_SESSION['serializedObj']);
$obj->dbReconnect();

code / content

$serializedObj = serialize($obj);
$_SESSION['serializedObj'] = $serializedObj;

There is one exception:

The PHP manual states that you have to include the class file before session_start(); and unserializing the object or else the object won't have a class reference and will be useless. However, using the method i detailed above, you MUST perform session_start() before anything else, then include, then unserialize. Anything less and you have a blank array.